Effect of angle stimulation during development on adult discrimination ability in rats

Hooded rats were reared in very restricted environments with angular, curved, or white-field stimulation. The extent of transfer from this exposure was assessed in adulthood by testing subjects for (a) learning ability in form, brightness, and pattern discrimination tasks, and (b) exploration and activity differences in an open field. The angle-reared group performed better than the other two rearing groups in all three discrimination tasks. Moreover, the curved and white-field groups were equivalent. These learning differences did not appear to result from differences in (a) exploration or activity or (b) dependence on kinesthetic cues. The results demonstrated that one type of early visual stimulation produced transfer to discrimination tasks that varied in difficulty and in degree of relevancy to the rearing forms. This effect was related to the results and interpretations from previous form-rearing studies. Three interpretations were proposed for this transfer and for the advantage of angular vs. curved stimulation.